Pipe



@et 21. w24: l 1,512,802 R- R RERTSON E T AL,

PIPE

Filed July 23. 1921 Naf Patented @et 21, 1924.

NTED STATES 1,512,802 PATENT OFFICE.

ROBERT R. ROBERTSON AND- CAR-L G. NAYLOR, CHICAGO, ILLINOIS, ASSIG-NORS TO NAYLOR-ROBERTSON COMPANY, A CORPORATION OF DELAWARE.

PIPE.

Application filed July 23, 1921. Serial No. 487,087.

To all 'whom it may concern.' f

Be it known that we'7 ROBERT R. ROBERTSON and CARL Gr. NAYLOR, citizens of the United States, all residing at Chicago, in the count-y of Cook and State of Illinois, have invented certain new and useful Improvements in Pipes, of which the following is a speciiication.

This inventio-n relates to pipes. f

It is particularly applicable to spirally wound lock-seam sheet metal substantially unyielding pipe.

Lock-seam spiral rigid pipe is ordinarily n made from strips of relatively easily worked and consequently soft metals, such as sheet iron and mild steel. Ordinarily the metal must be easily worked in order that ity will bend and not crack in the relatively abrupt curves ofthe interlocking spiral jo-int or seam. Y

An example of such pipe and a. machine4 for making the same is set forth in Patent No. 1,288,134, December 17, 1918.

It has been found that pipe of this character may be excessively worn, especiallyat the joint or spiral se-am, when the same is used to convey more or less abradant materials at relatively high velocities and under considerable pressure.

One of' the objects of this invention is to provide an improved pipe.

Another object is to reenforce the pipe against excessive wear from the passage of material therethrough..

Another object is to provide a pipe witha. wear resistant internal armor or li ing.

Other objects and advantagesv wi l herein after appear. y

An embodiment of the invention is illustrated in the accompanying drawing, wherein Fig. 1 is a perspective view of a spiral pipe as it appears from the outside.

Fig. 2 is a crosssection through the oint or seam of an ordinary spiral pipe.

Fig. 3 is a crosssection through thearmored seam of the improved pipe, and

Fig. 4 shows a cross-section through the seam of a modified construction, wherein the entire inner wall of the pipeis armored.

Spiral pipe comprises, in general, a tubel formed from a spirally wound strip of metal. Heretofore the joint interconnectlng the edges of adjacent convolutions or sections of the strip has been formed by folding the edges together to produce a suitable spiral lock-seam. Fig. 2 shows an example of such a seam in cross-section.

Particles of relatively hard materials conveyed through the pipe in the direction of the arrow impinge upon the spiraled surface A. This surface is more or less perpendcular to thepath of and faces the stream through the pipe. Then the material is driven at high velocity and under considerable pressure the particles strike this surface with great force and the resultant wear may v be excessive. In fact the pipe7 under some conditions,r may be worn through and destroyed'in a. comparatively short time.

In the improved pipe the tube is primarily composed of a spirally wound strip 1 of the softer sheetmetal as usual. The spiraled surface A and the inner wall of the pipe for some distance to the rear thereof are armored by a strip 2 of suitable wea-r resist-k ant material, suchas hard steel. The forward edge of thisfalrmoring or reenforcing strip is rmly clamped and held between the adjacent turned over and interlocking edges 3 and 4 of strip 1 which are folded together toform the spiraling lockeseam. It isnot necessary7 however, to bend the reenforcing strip .at such an abrupt angle as the strip forming the tube, because the reenforcing strip does not have to serve to hold the joint together, the strip is not a holding member of the joint. The rear portion or heel of the relatively hard reenfor'cing ystrip and the tube may be pressed together between the mandrel and forming rollsk with sufhcient force to embed the-*same substantially flushy into each other Yor .the tube wall may be gradually tapered inwardly at the heel of the reenforcingstrip,l as shown in Fig. 3. The

gradually tapering wall of the .tube at the heel of the reenforcing strip presents little or no obstruction to the passage of material. The material strikes the tube almost tangentially so that `there is little wear thereon.

The reenforcing and armorino' strip may be fed to a machine, such as set forth in the aforesaid patent, in the forni of a ribbon. The seam forming rolls bend the ribbon into the required shape and clamp the same between the folds of the spiral lock-seam and against the inner wall of theK tube as the seam is produced.

Fig. et shows a cross-section of pipe, Wherein the entire inner surface of .the tube is lined or armored and reenforced. A strip of relatively hard Wear resistant armoring material 6 has its forward edge rolled into and clamped .between the adjacent spiral seam forming edges 3 and l -of the main pipe, as before. The strips, however, are of such width that the rear edge overlies the seam of the adjacent anterior spira-l convolution and bridges the joint made by the seam.

instead of using an armor orlining of hard steel it may befouiid advisable, under' some circumstances, to protect the joint and interior of the pipe by strips of other materials. rlhus, for example, it may bev found Vadvisable, under some conditions to use Vstrips of rubber, leather, fabric` or otherinaterials. The joint packing action of the armoring strip composediof some of these other materials may surpassthat of the hard steel. Y n

Having described Vour linvention what we claim as new and desire to secure by Letters Patent, is:V ,Y Y

l. A substantially rigid pipe composed of sections joined together, and ar reenforcing wea-rY resistant armoring strip jon the inside of theY pipe, more resistant to wear than the body of the pipe, and held in place by the joint between thev sections.

2. A substantially rigid pipe composed of a spiral-ly wound metal strip, the edges ofl adjacent convolutions being folded over each other to form a spiral joint, and a reenforcing armoring strip, more resistant to wear than the body of the pipe located on the inside of the pipe and Vhaving an edge theretinuous spiral seam, and a reenforcing and armoring strip moreV resistant t-o abrasion than the body of the pipe wound in a spiral against the inside of the pipe and having one edge clamped and held in the folds of the spiral seam.

4. A substantiallyA rigid internallyk ar-Y mored pipe comprisingv a spirally wound metal strip the adjacent edges of which are folded together to provide an external'continuous lspiral seam, and a reenforcing strip of harder metal clamped between the folded edge-s forming the spiral seamy and spirally Wound to lie against the inside wall of the tube. 1

Y .5. An internally armored pippe comprising` a. .tube formed from a spirally wound metal strip the adjacent edges of which are folded together to provide an external continuous spiral seam, and a reenforcing strip of greatervear resistant material than the material of the strip clamped between the folded edges forming the seam and bridg-4 ing an anterior convolution thereof.

G. A substantially rigid` pipe composed ofv 1 'v a spirally wound metal strip, the edges of adj acent convolutons being foldedv over each otherl to form a continuously spiral joint, Y

and a strip of material, harder than the metal of the before mentioned strip, on the inside of the pipe, having its edge held between ,the edges of the spiraljoint.

A substantially rigid pipe composed of av spirally wound. metal strip, the edges ofA adjoining convolutions being folded over each other to form a joint and a third strip of harder material having its edge held between .the edges of the spiral joint, said strips being relatively immovable. v

ln testimony whereof we here-unto set our Y hands.

ROBERT R. R()BERTSON.l f CARL G. NAYLOR. 

